Engine control for motor vehicles



Sept. 7, 1954 K MAYBACH ET AL 2,688,259

ENGINE CONTROL FOR MOTOR VEHICLES Filed Dec. 28. 1949' 5 Sheefcs-Sheet l 3900 Rpm 4o 3000 fif MM WWI/93M 44 Sept. 7, 1954 K. MAYBACH ET AL 2,688,259

ENGINE CONTROL FOR MOTOR VEHICLES Filed Dec. 28, 1949 3 Sheets-Sheet 2 P 7, 1954 K. MAYBACH ET AL 2,688,259

ENGINE CONTROL FOR MOTOR VEHICLES Filed Dec. 28, 1949 3 Sheets-Sheet 3 1/10/1111, VIII/Ill. 4 I

VIII/20a 71/11/11 7 I Avril/111111,

Patented Sept. 7, 1954 Z,t&3,259

ENGINE CONTROL FOR MOTOR VEHICLES Karl Maybach and Richard Seifert, Friedrichshafen (Bodensee), Germany; said Seilert assignor to Maybach-Motorenbau G. m. b. H., Friedrichshafen, Germany, a German firm Application December 28, 1949, Serial No. 135,401

Claims priority, application Germany December 30, 1948 7 Claims. 1

This invention concerns a regulating arrangement of the type which is applied to power transmissions of power vehicles driven by means of internal combustion engines, and having a mechanical change speed gear and an automatic gear change apparatus. The invention is particularly useful for rail vehicles such as motorized rail cars and locomotives.

In such vehicles at a basic adjustment of the regulator member of the engine made by the operator (for example of the regulator lever for the supply of fuel which may be continuously adjustable over its range or adjustable in a few definite stages) the power output of the engine and the speed are exclusively determined by the travel resistances which must be overcome.

More especially in the case of rail vehicles the driver is not able to determine the correct instant for changing gear by judging the speed by the sound of the engine, as is possible with street vehicles. Thus with rail vehicles the driver usually changes gear too late i. e. the gear change is effected at a too high engine speed. The attention of the driver is also occupied in observing the track and the signals, and it is desirable that he should not be troubled with changing gear. For such vehicles therefore an automatic gear change apparatus (for example one dependent on the speed of the vehicle) is necessary for operating the change speed gears.

The known automatic gear change apparatus for mechanical gear changing could not, up to the present, he introduced to any great extent, because the driving engine, when using such automatic arrangements, must run very frequently with relatively high speed, resulting in noise, high strain and therefore considerable wear of the driving parts, impacts on the gears and also in high fuel consumption. It is an object of the invention to overcome these disadvantages.

According to the present invention, a regulating arrangementof the type referred to is provided in which, at basic adjustments of the regulating members of the engine, the power output of the engine is automatically altered by changing the fuel supply, which is regulated in dependence on the speed of rotation of the engine.

Thus a definite desired or. according to the driving conditions, required control of the engine output is produced within the range of speed of the change speed gear, so that the torque produced by the engine increases in a definite manner, or so that the output is kept uniform by the regulating arrangement at the basic adjustment.

The change of the gear ratio and the variation of mean cylinder pressure are preferably relatively to each other effected in such a manner that on changing gear no great difference in the tractive forces occurs (for example not more than 10% change), so that the driving conditions are not unfavourably affected by the gear change. This adjustment can also occur in such manner that the engine output remains about the same over the whole speed range. On changing from one gear to another the power output before and after gear change is practically the same, the tractive force graph showing no break at the moment of gear change. Particularly advantageous in this respect has been found a change in gear ratio from 1:2 to 1:3.

The regulation can however be so provided that greater power outputs are produced at the lower speeds than at the higher speeds within individual speed ranges, the outputs being greater than hitherto possible at the individual speeds. Thus the tractive forces after a gear change are greater than before.

The advantages obtained with a regulating arrangement in accordance with the invention are greatly enhanced if, in connection with the new regulating arrangement, the automatic gear change apparatus for the change speed gear is such that the speeds of rotation of the engine at which gear changes are eifected are changed ac cording to power output, so that at a smaller output automatic gear change is effected at a lower speed than at a greater output. Whereas in conventional devices the uppermost range of speeds of rotation is also used for driving with partial power, the invention provides lower rotational speeds when the output of the engine is reduced. The reduction of the gear change speed need not be effected at all basic adjustments or ranges of the driving power and. individual power ranges may use the same speed range, or the speed ranges may overlap to a greater or lesser extent. According to the invention an individual gear is used at partial outputs only so far that it produces speeds, which correspond to the range of speeds of rotation pertaining to the chosen power output.

To obtain especially high outputs through the regulating arrangement according to the invention, the charge of the engine is preferably increased at decreasing rotational speed.

A particularly advantageous arrangement is obtained if, at certain basic adjustments by the regulating means, the engine output between different gear speeds is automatically regulated in dependence on the engine speed according to a suitable law.

A centrifugal governor is preferably arranged to respond to a shaft speed ahead of the main clutch, which governor controls the fuel admis sion and, as the case may be, the moment of injection, one or two additional centrifugal governors being provided to be driven by a shaft between the main clutch and the change speed gear which additional governors effect the gear changes in the change speed gear.

The operation of a power vehicle provided with one form of a regulating arrangement in accordance with the invention is performed in such a manner that (at basic adjustments of the regulating members for the supply of driving medium to the engine) the output of the engine is automatically regulated in accordance with one or more driving variables, for example the speed of rotation of the engine, to follow a desired course, and that the speeds of the engine at which gear changes occur are lower at partial power production of the engine.

By the invention, fundamental difficulties are avoided, which have hitherto prevented the use of purely mechanical power transmissions in highly powered railway vehicles.

In addition to a mechanical change speed gear transmissions of another type may be used, especially turbo-converters.

The advantages of the invention are particularly great if change speed gears having a great numberof gear ratios, for example eight, are used. The system according to the invention produces better travel performances, less wear and greater driving convenience than conventional systems, even if they are provided with more than eight speed ratios. The extent of the available speed range is thereby considerably increased and the same vehicles can be used for different purposes. Locomotives for instance can be used both for freight and passenger service, which require considerably different top speeds so that the holding in reserve of vehicles is greatly simplified.

The fuel consumption of a vehicle equipped according to the invention is considerably lower than that of a vehicle of the usual construction since, when travelling at a definite speed the same engine output is obtained at lower engine speed, and with a more favorable compression.

The invention will be further described by way of example with reference to the accompanying drawings in which:

Figs. 1 and 2 are output and speed diagrams of a vehicle equipped according to the invention.

Figs. 3 and 4 are part sectional diagrammatic illustrations of mechanical arrangements according to the invention.

Fig. 1 shows output curves of a power transmission according to the invention for a rail vehicle, Nu designating the output curve for the lower gear change points, No that for the higher gear change points. The horizontal distance b tween the curves indicates the rotation speed range of the individual change speed gears at a definite partial power output adjustment. In this case the regulating arrangement according to the invention is so constructed that at a basic adjustment made by the operator the power output is maintained. If, for example, the driver adjusts a basic output of 60% (horizontal line denoted by 60%) and the speed of rotation is less than 1540 R. P. M. the speed will increase to 1540 R. P. M. and the output to 480 H. P. At a further increase of the speed of rotation of the engine the output will remain constant till a speed of 2000 R. P. M. is attained. If there is still an excess of power, a gear change into the next higher gear will be effected.

Fig. 2 shows the velocity of the vehicle in relation to the engine speed. If previously, for example, the 3rd speed gear was put in operation, the vehicle travels at 31 km./hr.; after shifting into the 4th speed gear, the travel speed beginning at 1540 R. P. M. of the engine will increase at constant power output of the engine to 41 inn/hr. whereupon shifting into the 5th speed gear is effected, and so on. In Fig. 6 the speeds of travel which are available at the basic adjustment are shown by heavy lines. With a basic adjustment of, for example, 25% shifting is performed within the range between 860 and 1120 R. P. M. Thus, to each basic power output adjustment, for example, by means of the fuel lever by the driver, there corresponds a definite speed range; within this range of speeds of rotation the engine can be operated at the preset output and the vehicle can be driven with any of the change speed gears, according to the prevailing travel resistance. This embodiment of the invention has the advantage that the whole range of the speed of rotation and of the output of the engine can be used in any desired fine gradation and the most favourable conditions can be produced.

The regulation of the driving power can be effected in any other manner than that which is illustrated and in which the driving power is constant at a definite basic power output. The output lines Nu and No may be continuous or may be variably curved, or may be irregular.

The dashed line pu in Fig. 1 shows the mean cylinder pressure corresponding to the lower output line Nu, the line 370 indicates mean cylinder pressure corresponding to the upper output line No, and the line on the mean cylinder pressure corresponding to a' constant power-output of 800 H. P. A further position of the regulating lever produces overload whereby the regulating arrangement produces a power output corresponding to the line Nit. The dashed line pii shows the mean eifective pressure at overload and the line 2160 illustrates the mean effective pressure for the described basic adjustment of 60%.

The points of intersection of the dashed lines 2280 and pn with the dashed lines 102/. and 270 indicate that the mean effective pressure produced by the system according to the invention is greater at the minimum speed of the speed ranges prevailing at each speed of the change speed gear at a certain fuel supply (and engine output) adjusted by the vehicle driver than at the maximum speed of the aforesaid speed ranges so that the tractive effort produced by the system is greater at the lower speeds of the speed. ranges than at the higher speeds and the tractive effort produced by the new system comes closer to the ideal conditions than in conventional systems. The aforedescribed result is produced by the supplemental fuel supply control means I94 to 205 which will be described later.

Fig. 3 is a part sectional illustration of a control system according to the invention for a locomotive driven by a diesel engine and having a change speed gear for four speed ratios. The engine power corresponds thereby to that shown in Fig. 1; the four speed gears produce the speeds of rotation and the car velocity lines shown for the gears I to 4 of Fig. 2.

In Fig. 3, numeral 3| designates the diesel engine provided with a fuelpump 32; 33 is the crank shaft of the engine on the end of which the casing 35 of a main clutch 34 is arranged; 36 are friction discs connected with the casing 35; 31 are friction discs connected with the driven shaft 38; 39 is a piston in a pressure oil cylinder 40 by which the friction discs are pressed. together against the action of a spring. II and 42 are small belt pulleys from which further pulleys 43, 44 and 45 are driven; 46 is a change speed gear of a type as shown, for example in Patent No. 2,352,212, the gear changes of which are effected by means of the piston rods SI and 52, of pistons 49 and 50, in cylinders 41 and 48, respectively. 53 and 54 are slide valves connected with the pistons 49 and 50, which are displaceable in guides 55 and 56 extending from the cylinders 41 and 40, respectively. 51, 53, 59, 50, 0!, 62, 63, 64 are control openings in the guides 55 and 56; 65, 66, 61, 68 are passages in the slide valves 53 and 54; 69 and are deaeration openmgs.

H is the housing of a regulating roller 12 with cams 13 and 14; 15 is a valve casing with bores 11 and 18, in which valves 19 and 80 are displaceable; 9! and 83 are connecting passages between the bores 11 and 18; 82 is a connecting passage to the outside; 94 is a passage for the supply of oil pressure; 85, 86 are recesses in the bores 11 and 19; 91, 88, 89 and 90 are passages to which pipes 92, 9|, 93, 94, respectively, are connected which lead to the cylinders 41 and 48. 95 and 96 are compression springs; numerals 91 and 9B designate openings connecting the housings of springs 95 and 96 with the outside. I00 is a pressure oil supply pipe which forks into two pipes IM and I02. The pipe IOI branches into two pipes I03 and I04. From the pipe I02 branches a pipe I05, and from the latter a pipe I06. The two pipes I00 and I09 unite in pipe IIO, which forks into two branches III and H2. The pipes II 3 and H4 combine to form the pipe H5. The pipes I05, I06, I09, I09 terminate in the valve guide 55 and the pipes III, II2, II3, II4 terminate in the valve guide 56. Pipe I I6 is connected with the pressure oil cylinders 40 of the main clutch 34. I2I and I22 are two centrifugal governors which are driven by the pulleys 44 and 45, respectively, and act on slide valves I23 and I24 having recesses I25 and I26, respectively. These slide valves are displaceable in housings I23a and I24a, respectively. I21, I29, I29, I are regulating openings in the housings I 2311 and I24a; ports I3! and I32 connect the housings with the outside; I33 and I34 are compression springs; I35 and I36 are small pistons; I31 and I38 are connection pipes between the casings I23a and I24a and the cylinders I39, I40, respectively, in which pistons I4 I, I42 are displaceable against the pressure of springs I43, I44. Piston rods I45, I45 act through pawls I41 and I48 on ratchet wheels I49 and I50, respectively, which are arranged on the axle I5I of the regulating roller 12. The two pawls I41 and I48 one of which lies on the front side, the other on the rear side of the re-.

spective ratchet wheel, are so far removed from the ratchet wheels, when in rest position, that if one pawl is engaged, the other pawl is ineffective.

Numeral I58 designates a cam disc which can be rotated by a lever I59. The circumference of the disc I forms three cams of which the first, I60, begins with a raised portion I6I. Cam I60 can be engaged by a pin I62 which is arranged at the lower end of a slide valve I63 which has an annular cavity I64 and is displaceable in a housing I66 against the pressure of a spring I65.

I61 is an aperture connecting the housing I66 with the outside; I68 is an opening to which the pipe I I5 is connected. I69 is a port which is connected by a pipe I10 with an opening I12 in a cylinder III in which a piston I13 is displaceable against the pressure of a spring I14. A pin I15 is connected with the piston I13. I16 is an opening in the housing I1I to which the pipe H6 is connected.

I89 is a hand lever which is pivoted at I8I and has an arm I92 on the lower end of which a roller I83 is arranged, which roller can bear upon the cam I94 of the cam disc I58. To the lever I02 a short rod is pivoted at I85, a spring plate I66 being connected with the small rod and disposed in a cylinder I89 against one end wall of which the spring plate is pressed by a spring I81. ItIa is a tension spring. The cylinder I63 is connected to a bell crank lever I89 by a small rod I90a. The bell crank lever I89 is connected with a crank pin I9I through a rod I90. This pin MI is arranged on a gear wheel I92 which meshes with a gear wheel I93. I94 is a centrifugal governor driven by the pulley 43 for axial displacement of a cam I95, the latter can be simultaneously rotated by the wheel I93. The cam I95 has two cam surfaces. On one cam surface I96 lies a roller I91 which regulates the amount of fuel fed by pump through a bell crank lever 290. 20I is the other cam surface of the cam I95. On this lies the roller 202 which, through a two-arm lever 203 and a rod 204, acts on a bell crank lever 205 and thereby adjusts the injection moment of the fuel pump. The rollers I91 and 202 are pressed against the cam surfaces I96 and mi by springs 206 and 201, respectively.

Cam 2E0 has an ineffective (circular) portion 2I0a which is engaged at the beginning of a counterclockwise rotation of the cam by a roller 2II which is held in contact therewith by a spring 2.!3. The roller 2II is mounted on the free end of a two-arm lever 2 I2. The other end of lever 2 I2 is connected to a rod 2 I4 on which two angular levers 2I1, 2I9 and 2I8, 220 are pivoted at 2 I5, 2I6, respectively, which press against the small pistons I35 and I36, respectively. 22I is a lever arm connected to the lever I82. At the end of arm 22L a plate 222 is arranged against which the peg I1 5 can abut.

In the first gear the pistons 49 and-50 both stand in their left hand end position, in the second gear the piston 49 is in the right hand position and the piston 50 in the left hand end position.

For the third gear the piston 49 stands in the left hand position, the piston 50 in the right hand position, in the fourth gear both pistons stand in the right hand position.

Fig. 4 illustrates a partial section through the valves 53, 54 and also through the valve I24 in another radial plane than the sections shown in Fig. 3. Besides the previously described numerals, 23I is a pipe branching oif the pipe I06; numeral 232 designates a cross passage in the valve I24. 233 and 231 are connecting pipes; 234, 235, 236 are pasages in the valve 53; 238, 239, 240 are passages in the valve 54; MI is a connection pipe to a cylinder 242 interposed in the pipe II5, to which is connected also a pressure oil pipe 243. A spring 245 presses on a slide valve 244 arranged in the cylinder 242 from the left, the slide valve 244 having a cross passage 246 and a groove 241.

In Fig. 3 the various parts are shown in the positions which they assume when the vehicle is stationary. The hand lever. I59 stands in the on position. The engine 3I stands stillas well as the centrifugal governors I-2I, I22 and I94. In the change speed gear, the first gear has been engaged. The piston 49 is therefore in its left end position in its cylinder 41, as also does the piston 58 in its cylinder 48.

The pipe I39 and the whole oil system'receives no:oil pressure since the oilpump (not shown) is not yet running. The rods I 99, 205) for the adjustment of the amount of fuel fed by pump 32, and the members 254, 205 for the adjustment of the injection point moment are in the position of smallest feed and smallestpreinjection. The pin I62 and the roller 2II engage the ineffective cam portions itI and 2I9a'at the beginning of the cams I53 and 2H), respectively, the roller I83 being pressed: by the spring I81a against the highest point of the cam I84. The

slide valve I63 stands in its'lovvest position so that, as may be seen from the drawing, the pipes I10 and H5, and thereby the space of the cylinder 4%} on the right of the piston 39 are connected with the outside through the port I61. The main clutch 34 is held in disengaged positionby the clutch spring.

The engine SI will now be started and run with low speed. The governor I94 is driven by the chain connecting pulley M to pulley 43. The governors IZI and I22 are driven by the pulley 42 through pulleys 44 and 45. Pressure oil is'now supplied to the pipe I90 and passes through the pipes I32, I95, I69, the opening 58, the passage 6t, the opening the pipes I98, I99, IIO, III, the opening 52, the passage 51, the opening 84 and the pipes I I3 and I I5 to the cylinder I66 in the spaced form by the-recess I64 of the valve I63. Up to this moment the position of none of the members of the apparatus has been changed.

If the driver moves the hand lever I59 through a certain angle upwards, and thereby rotates the cam disc I53 counterclockwise, the pin I62 passes on to the raised part of the cam I50. The peg I62 and with it the slide valve I63 are so far upwardly displaced, that the connection. of the pipe I19 with the opening I 61 is interrupted and pipe I10 is connected with the pipe II5. by the recessed portion I64 of the slide valve I63.

Pressure oil now passes from the pipe H5 into the pipe I13 and under the piston I13-as well as into the pipe H5 and to the cylinder 49. The friction clutch 34 is engaged through the oil pressure acting on the piston 39. The vehicle starts to move. The cam I 95 is rotatedby. the roller I t3 lying against the cam track I34 and through the transmission I82, I36-I93, whereby amount of fuel and the injection moment corresponding to the changed load and speed of rotation is adjusted. Upon acceleration of the.vehicle, the cam I95 is further displaced to the right by the governor I94 and the fuel feed and the moments of injection are continuously adjusted according to changing speeds of the engine shaft. The springs I33 and I34 of the governors I H and I22, respectively, are slightly compressed by. the pistons I35 and I36, the pressure of pistons I35 and I35 being caused by displacement, of the cam 2m and consequent movement of the members 2H, H2, H1, 2I9 and 2I8, 220. The fundamental adjustment made by the driver cor responds to power output of the engine which accelerates (as seen in Fig. 1 to a speed of 860 R. P. M. The vehicle. obtains thereby a 8 speed of travel of 8 km./hr. If the driving'resistancesare so small that there is too much power available, the speed of travel and the engine speed both increase further. At the same time, corresponding to the increase in speed, the cam I95 is displaced'farther to the right by the governor I94 and the amount of fuel, and the injection moment are so altered that the power output of the engine remains about the same (straight lines parallel to the abscissa axis in Fig. 1). This lasts until the engine speed of 1120 R. P. M. (speed of travel 11 km./hr.) is attained (Fig. 2). At this speed of rotation which is determined by the tension exerted on the spring I33 by, the cam 2I0, the pendulum I2I effects gear shifting by moving the slide valve I23 towards the left. The recessed portion I25 connects the pipe I 93 to the pipe I31 and pressure oil passes through the pipes I III, I33, I31 into the space above the piston I4 I, which is displaced downwards so that roller 12 is rotated clockwise (as seen from the left) by means of the pawl I41 and the ratchet wheel 549 so that the slide valve 19 is moved up into the recess 13 by the spring 95. While previously pressure oil is fed from the pipe I92 through the passage 84, the recess 86 of the slide valve 80, the passage 83, the recess 85, the passage 93 and the pipe 9I to the space on the right of the piston 49, this space is now connected, in the upper end position of the slide valve 19, through the passage 88 and the opening 91 with the outside, and the passage 83 is connected through the recess with the passage 81 and through the pipe 92 with the space of the cylinder 41 to the left of the piston 49.

Thereby the piston 49 is moved towards the right, disengaging the claw clutch of the first gearand engaging the claw clutch of the second gear after the decrease of the speed of rotation down to 860 R. P; M.; prior to engagement of this new gear ratio the connections of the passage 66 through the port 59 with the pipe I08, and through the opening 58 wth the pipe I06, are both interrupted, and the passage 56 is connected with the outside through the opening 69. Thereby the oil pressure is relieved in the pipes I99. IIil, III, through the passage 51 and the pipe H5, and in the space under the piston I13 as well as in the pipe I I6 and in the cylinder 40 in front of the piston 39. The friction clutch 34 is thereby disengaged. The downward movement of pin I15 under the action of the spring I14 is transmitted to the plate 222 and the lever 22I, swinging the lever I82 to the left and raising the roller I83 from the cam I84. The amount of fuel and the injection moment is thereby automatically adjusted to smaller values during the gear change and the speed of rotation is reduced so that the new claw clutch can engage.

In the right hand end position of piston 49, the pressure oil from the pipe I05 can pass into the pipes I I3 and H5 through opening 51, the passage 65 in the slide valve 53, the opening 59,

the pipes I98, II9, III, the opening 52 and the passage 61, and from conduit H5 under the piston I13, forcing it upwards. Oil pressure builds up also in the pipe H6 and in the cylinder 40 on the right of the piston 33, engaging the clutch 34. At this time the roller IE3 is again pressed against the cam I84 by the lever I82 and the spring I81a, and thereby the amount of fuel and the moment of injection are adjusted according to the prevailing speeds of rotation.

The, change from the second into the third speed gear and from the third into the fourth gear is performed in substantially the same manner as is the change from the first into the second gear. Continued counterclockwise of the hand lever I59 causes continued pressure oil supply to the cylinder 40, due to the action of the cam I60, control of the friction clutch 34. The fundamental adjustment of the engine output by controlling the fuel supply and the fuel injection moment is determined by the cam I84 according to the angular position of the cam. The tension of the springs I33 and I34 is regulated by the cam 2I0, whereby the gear change speed is adjusted.

The governor I94 automatically adjusts the amount of fuel and the injection moment according to the prevailing engine speed, determining the power output of the engine in the desired manner. If the speeds of rotation corresponding to the basic output are attained, the

upward and downward gear change is auto- H matically effected by the governors I2I and I22.

The downward gear change proceeds in a similar manner as the above described upward gear change. If the vehicle travels at a definite basic adjustment of the engine output, e. g. 60% in the fourth gear with a speed of 35 km./hr., the engine runs (as may be seen from Fig. 2) with a speed of 1710 R. P. M. The pistons 49 and 50 are in their right hand end positions. On increase of the driving resistance, the speed of travel is reduced and therewith the speed of the engine, and on reaching 31 km./hr. and 1540 R. P. M., the pendulums of the regulator I22 have moved inwardly so that the opening I32 is closed by the left hand part of the slide valve I24 and the pipe I33 is connected by the recess I26 of the slide valve I24 with the pipe I04 (in the position shown in the figure).

The oil pressure displaces the piston I42 downwardly and rotates the regulating roller I'I2 counterclockwise (seen from the left) through the pawl I48 and the ratchet wheel I50 into a position which corresponds to the third gear. The piston 43 travels to the left on account of the new adjustment of the slide valve I9 whereby the friction clutch is disengaged in the same manner as above described. After engagement of the claw clutch halves of the third speed gear, the amount of fuel is again increased due to contact of the roller I83 with the cam I84, the speed is increased, the friction clutch engaged, and the claw clutch halves ratcheting over one another are engaged on attaining the overtaking speed of rotation, in this case 2000 R. P. M. (Fig. 2).

The mechanism for this latter operation at a downward gear change is shown in Fig. 4. The section through the valves 53 and 54 lies in another plane than that shown in Fig. 3. The slide valves 53 and 54 are otherwise formed in the same way as shown in Fig. 3. The pendulums of the centrifugal governors I2I and I22 are in the innermost position when the engine stands still. The spring I34 is so designed and tensionecl that as soon as the engine runs even at a low speed of rotation below 500 R. P. M. the pendulums 22 move into their outer position in which the pipe I38 is connected by the recess I26 of the slide valve I24 with the opening I32. Ac-

cording to the pressure acting on the slide valve I24 through the spring I34, 1. e. according to the position of the cam disc I58, and thus according to the power produced by the engine, the speed of rotation at which the pendulums move inward, i. e. the lower gear change speed, is increased. When the lower gear change speed has been attained, and the pendulums I22 pass into the inner position so that the slide valve I24 assumes the position shown in Fig. 4 and brings about the gear change as described. Pressure oil will be fed through the pipe 23 I, the passage 232 and the pipe 233 to the slide valve 53 of the piston 49. In the end positions of the piston 49, the oil can pass through the passages 236 or 234 into the pipe 23? and to the slide valve 54 of the piston 50. Since the piston 43 when shifting from the fourth speed gear into the third speed gear, must be displaced from its right into its left end position, as soon as the previously engaged claw clutch is disengaged and the clutch halves to be engaged are in overrunning position, piston 4e being approximately in the middle position (as indicated in Fig. 4), the passage for the pressure oil through the pipe 23! and through the pasage 238 towards the pipe MI is free. The slide valve 244 will be displaced by the pressure oil into its left hand position, in which position pressure oil can pass from the pipe 243 through the groove 24? into the part of the pipe I I5 leading towards the left. Whereas the pipe H5 in the above described manner (through 60, 66, 69) was connected with the outside, pressure oil is now supplied through the left part of the same, pipe M5 to the piston I13 and through the pipe M5 to the cylinder 40 to the right of the piston 33. The friction clutch is thereby engaged, the roller I83 is laid against the cam track I84 and the speed of rotation of the engine is increased by the increased fuel supply. The gear change clutch half to be engaged is rotated at a speed at which it can be engaged, engagement being effected by the piston 49 travelling to the left. The pendulums I22 move the slide valve I24 again into the normal left hand end position, the pressure oil supply against the right hand end of the slide valve 244 ceases, so that valve 244 returns to its right hand end position, and connection of the two parts of the pipe H5 is again effected through the passage 246.

If the piston '53 in the cylinder 48 effects a downward gear change, the presure oil adjusting the slide valve 244 can pass through the assages 234 or 236 in the slide valve 53 and through the passage 239 in the slide valve 54.

We claim:

1. A control system for vehicles driven by an internal combustion engine comprising, in combination, a change speed gear including a drive shaft, an automatic gear change apparatus responsive to the speed of said drive shaft for changing the gears of said change speed gear at predetermined drive shaft speeds, a centrifugal governor driven by the engine, a first cam member adjustable by said centrifugal governor, a cam on said cam member, a first linkage having an element in contact with said cam, means responsive to the movement of said linkage for changing the rate of fuel supply to said engine, a second cam member adapted to be actuated by the vehicle driver, a first and a second cam on said second cam member, a second and a third linkage, each of said second and of said third linkage having one element in contact with the first cam and with said second cam, respectively, of the second cam member, means responsive to the movement of said second linkage for varying the position of said first cam member, and means responsive to the movement of said third linkage for adjusting the engine speeds at which said automatic gear change apparatus changes the gears of said change speed gear.

2. A control system as defined in claim 1 in which the automatic gear change apparatus includes a pair of governors, housings for said governors, pressure oil supply conduits connected to said housings, apertures in said housings, affording flow of oil therethrough at predetermined positions of the governors, means responsive to the flow of oil through one of said housings to change gear upwards, means responsive to the flow of oil through the other of said housings to change gear downwards, each of said housings containing a piston movable therein and a spring interposed between said piston and the governor of the respective housing, and movement transmitting means connected with said third linkage and with said pistons for moving the latter against said springs and changing the tension of said springs and thereby changing the engine speeds at which said automatic gear change apparatus changes the gears of said change speed gear.

3. A control system for vehicles driven by an internal combustion engine comprising, in combination, a change speed gear including a drive shaft, an automatic gear change apparatus responsive to the speed of said drive shaft for changing the gears of said change speed gear at predetermined drive shaft speeds, a centrifugal governor driven by the engine, a first cam member adjustable by said centrifugal governor, a pair of cams on said first cam member, a first linkage having one element thereof in contact with one of said cams, a second linkage having one element thereof in contact with the other of said cams, means individually connected with and responsive to the movement of said linkages for varying the rate of fuel supply and the moment of injection, a lever adapted to be actuated by the driver, a second cam member connected with said lever, a first and a second cam on said second cam member, a third and a fourth linkage, each of said third and of said fourth linkage having one element in contact with the first cam and with said second cam, respectively, of the second cam member, means responsive to the movement of said third linkage for varying the position of said first cam member, and means responsive to the movement of said fourth linkage for adjusting the engine speeds at which said automatic gear change apparatus changes the gears of said change speed gear.

4. A control system as defined in claim 3 in which said automatic gear change apparatus includes a pair of governors, housings for said governcrs, pressure oil supply conduits connected to said housings, apertures in said housings, affording fiow of oil therethrough at predetermined positions of said governors, means responsive to the dew of oil through one of said housings to change gear upwards, means responsive to the flow of oil through the other of said housings to change gear downwards, each of said housings containing a piston movable therein and a spring interposed between said piston and the governor of the respective housing, and a pair of bell crank levers connected with and movable in response to the movements of said fourth linkage, said bell crank levers being individually connected with said pistons for moving the latter against said springs and changing the tension of said springs and thereby changing the engine speeds at which said automatic gear change apparatus changes the gears of said change speed gear.

5. A control system for vehicles driven by an internal combustion engine, comprising, in combination, fuel supply control means adjustable by the vehicle driver, a mechanical change speed gear including a drive shaft, an automatic gear change apparatus responsive to the speed of said drive shaft for changing the gears of said change speed gear and comprising means connected with said fuel supply control means for effecting the gear changes at higher engine speeds when the fuel supply is greater and for maintaining substantially the same minimum and maximum engine speeds for all speeds of said change speed gear at the same fuel supply adjusted by the driver, automatic control means connected with said fuel supply control means and being responsive to the speed of the engine for increasing the fuel supply beyond the fuel supply adjusted by the operator, at the aforesaid minimum speeds and for decreasing the fuel supply to the fuel supply adjusted by the operator as the engine speed increases to the maximum speed at which a gear change is effected at the fuel supply adjusted by the operator for increasing the mean effective pressure of the engine beyond that which is normal at the minimum speeds of the speed ranges of the individual gears of said change speed gear at the engine output corresponding to the fuel supply adjusted by the operator and for effecting a mean effective pressure of the engine at the maximum speeds of the speed ranges of the individual gears of said change speed gear which pressure is substantially normal at the engine output corresponding to the fuel supply adjusted by the vehicle operator.

6. A control system according to claim 5, said fuel supply control means comprising a cam member adapted to be rotated by the vehicle operator and having a circumferential cam surface and an axially extending cam surface, and said automatic control means comprising a centrifugal regulator connected with the engine and with said cam member for axial displacement of said cam member according to the speed of the engine.

7. A control system according to claim 5, said fuel supply control means comprising a cam member adapted to be partially rotated by the vehicle operator and having two cams, each of said cams forming a circumferential cam surface and an axially extending cam surface, said automatic control means comprising a centrifugal regulator connected with the engine and with said cam member for axial displacement of said cam member according to the speed of the engine, a fuel pump, first cam follower means engaging one of said cams and being connected with said fuel pump for controlling the fuel supplied to the engine, means for injecting the fuel supplied by said pump, and second cam follower means engaging the other of said cams and being connected with said fuel injection means for controlling the moment of fuel injection into the engine.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,701,274 Rabbidge Feb. 5, 1929 2,008,231 Vincent July 16, 1935 2,089,590 Walti Aug. 10, 1937 2,178,356 Brunner Oct. 31, 1939 2,213,683 Banning Sept. 3, 19-10 2,283,284 Owner May 19, 1942 2,303,951 Oswald Dec. 1, 1942 (Other references on following page) 13 14 UNITED STATES PATENTS Number Country Date 889,074 France Dec. 30, 1943 2 5 53 5 gi' f Dec 924,103 France Jan. 28, 1947 2,330,388 Scott-Paine Sept. 28, 1943 5 OTHER REFERENCES 2,352,212 Lang J1me 27, 1944 Ser. No. 221 826 Stie litz (A P. C.) ublished 2,422,850 Porter June 24, 1947 May 18 g p FOREIGN PATENTS Report on Development of Petrol Injection Engine (British Intelligence Objectives Sub-Com- -fzggg g g f g fi m mittee), Maybach H. L. 234, issue date 1947. 

